Fractionating tower



Dec. 3, 1940. D DODDS 2,223,556

FRACTIONATING TOWER Filed March 21, 1938 2 SheetsSheet l Dec. 3, 1940. DODDS 2,223,556

FRACT I ONAT ING TOWER Filed 'March 21, 1958 2 Sheets-Sheet 2 Patented Dec. 3, 1940 UNITED STATES PATENT OFFICE FRACTIONATIN G TOWER Tax.

Application March 21, 1938, Serial No. 197,164

5 Claims.

This invention relates to a fractionating tower. An object oi the invention is to provide apparatus of the character described specially designed to be employed for the purpose of sep- 5 arating the lighter elements of a fluid fromthe heavier elements thereof in an approximately horizontal chamber.

More specifically the invention relates to apparatus designed to be employed in fractional distillation, absorption, condensation or stripping of liquids or gases as the same moves in an approximately horizontal direction through the tower.

Another object of the invention is to provide apparatus for accomplishing the above purposes that will be safer and more economical than apparatus now in common use for accomplishing such purpose.

In the construction of the invention hereinafter described few fittings are employed, that is to say, the number of valves, flanges, pipes and the like have been reduced to a minimum so as to reduce as much as possible the potential hazards both to operators and to the equipment itself due to flaws and breakage of such fittings. A loss of operating time will be correspondingly reduced because of flaws of such parts thereby also reducing the cost of maintenance, work and material. The weight of the horizontal fractional distillation equipment is distributed over a larger surface than the conventional type of tower thereby eliminating a considerable portion of the foundation as well as much of the expensive steel structure necessary to maintain the vertical tower in vertical position. Accordingly, the type of horizontal tower herein disclosed will be more economical as to its original construction, as well as to its subsequent maintenance than the conventional type of vertical tower in common use.

A further object of the invention resides inthe provision of a horizontal type of construction embodying a novel type of partition assembly that divides the container into sections which presents a much larger area, for the arrangement of vapor passagewaya than is possible with the conventional type of construction, for the reason that it is unnecessary to use such'a large portion of each partition assemblyfor the liquid downflow passages and sealing pans. The type of assembly employed is suspended in a vertical position instead of a horizontal position, as'in the conventional type of construction, can be constructed of much lighter material eliminating a great deal of weight and economizing the valuable displacement space in the tower;

It is a still further object of the invention to provide a tower of the character described which is of such construction that the perimeter of the 6 bubbling caps employed can be increased, over that of the conventional type in a vertical tower,

without decreasing the number of bubbling caps,

this result being accomplished by increasing the length of each bubbling cap thus allowing the 10 working conditions to bequickly and easily changed by merely changing the capacity of the in this specification and illustrated in the accom- 25 panying drawings, wherein Figure 1 shows a vertical, sectional view of the apparatus illustrating an embodiment of the principle involved.

Figure 2 shows a cross-sectional view taken on 30,

the line 2--2 of Figure 1.

Figure 3 shows a fragmentary, horizontal, sectional view taken on the line 3,-3 of Figure 2,

and

Figure 4 shows an enlarged, perspective view of 5 V a bubble cap employed.

Referring now more particularly to the drawings wherein like numerals of reference designate the same parts in each of the'flgures, the numeral i designates the outer casing or container which is so disposed that-the fluid will follow, in general, an approximately horizontal course from inlet to outlet. Mounted in the casing, and spaced apart, are similar vertical partitions as 2. Any selected number of parti- 45 tions may be employed and they may be spaced the required distance apart to provide the intermediate chambers. The end partitions are spaced a suitable distance from the ends of the container I thus providing the end compartments 5( 3, 4. Each plate 2 ispro'vided, near its lower margin, with a transverse. return slot 5 and, in, front of .said slot, is provided with a transverse baflie 6 which extends upwardly the required distance above the upper margin of the corre- 55 sponding slot thus providing for the return of the residue from compartment to compartment. Anchored in said intermediate compartments and in the compartment 4 are the collecting pans 5 7 preferably arranged one above the other. Suitably anchored to the respective partitions are the bubble caps designated generally by the numeral 8 in Figure 4. 1 Each cap is formed with a tubular neck 9 which communicates with the compartment in front of the partition to which said cap is anchored and whose free end I!) is downwardly turned and serrated. The downwardly turned ends of the caps are preferably, although not necessarily, rectangular in cross-sectional contour and may be of any selected dimensions depending on the bubbling capacity desired. The free margins of the downwardly turned portions of the caps extend down into the pans I beneath the required distance and the downwardly turned ends of the caps of the lower series extend a distance beneath the upper margins of the corresponding baiiies 6. Delivery tubes ll lead from each upper pan, at one end, into the corresponding end of the pan beneath and depending from the other end of said last-mentioned pan is the delivery tube l2. The upper ends of said tubes extend up into the corresponding pans, from which they lead, up to the desired level'of the liquid in said pans. Accordingly, the liquid entering a pan from the pan above will travel along the receiving pan from end to end to the point of discharge.

,The fluid to be fractionated enters the compartment 3 and collects at the bottom of the tain a heating coil I! if desired through which a heating medium may be circulated through the pipe l5. Other heating means may be employed, if desired, or in some cases this heating element may be dispensed with. Leading from the compartment 3 there is an outlet line l6 whose inner end extends up into said compartment to the desired. liquid level and is surrounded and enclosed by an inverted hood I1 forming a trap. This hood may be supported in any selected manner. The lighter elements given off from the fluid collected in the compartment 3 will pass through the respective bubble caps in the direction indicated by the arrows in Figure 1 and the entrained heavier particles there- .in will be condensed and will drain down into the pans so as to eventually maintain the lower serrated edges of the caps submerged, the lighter elements bubbling through the entrapped liquid and passing on from one series of bubble caps to the next and eventually collecting in the compartment I and. passing outwardly through the vapor outlet line l8.

The top or highest pan of each series will collect suflicient condensate or liquid to rise to the level of the top of the corresponding delivery tube l I and will overflow it and will flow down into the next succeeding pan below whereby the level of the liquid in any particular pan will be controlled. The pans will thus collect and thereafter maintain a suflicient quantity of liquid to submerge the serrated ends of the bubble caps the excess finally reaching the bottom of the corresponding compartment and will return from compartment to compartment through the slots 5 overflowing the corresponding baflies 6 and rising to a level to submerge the lower serrated ends of the lowerbubble caps as shown. Eventually, the residuum will drain out through the outlet line l6. It will thus be observed that the compartment 3. Said compartment may 'con-' liquid as it collects will pass from pan to pan and will finally collect at the bottom of the corresponding compartment and will pass thence from compartment to compartment to the point of discharge. This is a very desirable feature as it allows the particles of the lighter fraction or constituents of lower boiling point to pass on rather than to be entrained in constituents of a Higher boiling point and to be carried back along the tower where it may pass out as residue. The course of travel of this liquid is several times greater than that of the conventional fractionating tower.

In this type of equipment during operations there is a continuous flow of vapor forwardly through the tower until the vapor reaches the final compartment in the present illustration is indicated by the numeral 4 and from which it is conducted out through the vapor outlet line l8 and there is also a continuous flow of the liquid backwardly or in the opposite direction to the forward movement of the flow of the vapor.

It is sometimes desirable to admit additional liquid for refluxing or for the purposes of absorption. For this purpose a line I9 hasbeen provided which leads from a suitable source of refluxing or absorption liquid and whose discharge end 20 is extended downwardly through the top of the tower and terminates beneath the level of the liquid in an upper pan I in one, or more, of the compartments. As shown it terminates in the upper pan 1 of the final compartment 4 and is thus sealed from the vapor in the corresponding compartment.

It will usually be desirable to provide means for leading off the products collecting in the various compartments between the partitions 2. The illustration .shows an outlet line 22 leadin from one of said compartments and whose upper end is surrounded by a cap 23 which is anchored in any suitable manner in the casing l and which is spaced from the free end of the line 22. The lines l9 and 22 will be controlled by control valves suitable for the purpose.

The drawings and description disclose what is now considered to be a preferred form of the invention way of illustration only, while the broad principle of the invention will be defined by the appended claims.

What I claim is:

1. A fractionating tower, approximately vertical partitions therein separating the tower. into compartments, transverse pans in the compartments arranged one above the other, bubble caps anchored to the partitions and having downwardly turned ends extended into pans through which the vapors may pass from compartment to compartment and delivery tubes through which the liquid in the pans may overflow from pan to pan and from the lower pans into the compartments beneath. 1

2. A fractionating apparatus comprising a tower arranged approximately horizontally, vertical partitions in the tower separating the tower into end compartments and into intermediate compartments, one end compartment having an inlet and the other end compartment having an outlet, a plurality of vertically arranged bubble caps connected to each of the partitions and effective to permit the advance of the vapors from the inlet to the outlet, means cooperating with the bubble caps for separating the heavier fractions from theadvancing vapors and for collecting said separated heavier fractions in the bottom of the compartments and means for permitting the return flow of the heavier fractions so separated from compartment to compartment.

3. A fractionating tower having approximately vertical partitions therein separating the tower into compartments, transverse collecting pans in the compartments arranged one above the other in tiers, bubble caps anchored to the respective partitions and having downwardly turned ends with serrated margins extended into the pans through which the vapors may pass from compartment to compartment, delivery tubes through which the liquid condensed by said bubble caps into the pans may overflow and from the upper pans into the lower pans and thence into the compartments beneath.

4. A fractionating tower having vertical partitions therein separating the tower into end compartments and intermediate compartments, one end compartment having an inlet and the other end compartment. having an outlet, transverse pans in some of the compartments arranged in tiers, one above the other, bubble caps anchored to the partitions and having their forward ends downwardly turned and serrated, whereby the vapors are permitted to advance through said caps from compartment to compartment from the inlet to the outlet, the downwardly turned ends of some of said bubble caps extending into the corresponding pans and forming condensing means for stripping the heavier fractions from the lighter fractions, means for permitting the overflow of the liquids from the upper to the lower pans and from the lower pans into the compartments beneath.

5. A fractionating tower having vertical partitions therein separating the tower into end compartments and intermediate compartments, one end compartment having an inlet and the other end compartment having an outlet, transverse pans in some of the compartments arranged in tiers, one above the other, bubble caps anchored to the partitions and having their forward ends downwardly turned and serrated, whereby the vapors are permitted to advance through said caps from compartment to compartment from the inlet to the outlet, the downwardly turned ends of some of said bubble caps extending into the corresponding pans and forming condensing means for stripping the heavier fractions from the lighter fractions, means for permitting the overflow of the liquids from the upper to the lower pans and from the lower pans into the compartments beneath, and means for leading off the liquid collecting in said compartments.

DAN L. DODDS. 

